Loud-speaking sound producer for telephones



ETAL.

Apr-13H 23 19290 Filed April 18, 1925 Invenhnrs:

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"r nrrz wmnnniuor c scum) 1230191161 31 I 3' L P N S v 'ip licaiom April 18,192; Serial Nor-"24,137, and 'in Germany May 12, 1924s"- Our invention relates to a loud -spe'aking sound producer for telephones, particularly for the purposes of wireless telephony.

v The object oflour'invention is to provide 5 a sound producer reproducing tones and sounds of all kinds sonorously, clearly and in their natural timbre.- I

With this object in view, our invention consists in such an arrangement that the armature of a telephone receiver, has an oscillation-transmitting connection with a resonance board and that the resonance board is forming a part of a resonating y- 1 v Preferabl the resonance board and the resonating ody are made of wood. This arrangement has the advantage that by suit- 'ably prop'ortioning the resonance board as well as the other parts ofthe resonating body the sound producer vmay reproduce both high and deep tones in such a manner that-v not only human speech, but also the differ ent' kinds of musical instruments'may be brought to reproduction'clearly and'in then natural timbre and without disturbing sec- V obvious that various other embodiments ondary sounds. A p

The invention consists'of structural characteristics andrelative arranigfililnent of elements to be hereinafter more y described and particularly pointed out in the appended of'drawings similar refclaims. 4

In ,the' one sheet erence characters indicate 'the s'aine parts in the two figures, in which Figure 1 is a transverse longitudinal sectio partly in elevation of t e invention, an

Figure 2 is a top plan view. In the preferred form of the iDvcDtlOII as 40 shown in thedr-awings, the telephoneelectromagnet 1 is journalled upon--a screw .40 rotatable in a seating 41, but is itself prevented from rotation with respect to the seating by means of a special transverse piece. The screw 40 rotatable in the seating 41 isprovided with an exterior handle 42 by rotation of which the telephone electromagnet can be adjusted longitudinally of the sound producer. I

The seating 41 is fastened by screws to the wooden ring 12 on which'is alsoarranged the armature 5. The laminated ring 12 is secured to the floor 16 of the sound box, the cover of which is constituted by the sounding board 9. The sound box 1s preferably OFFICE? 7 constructed of wood', and a cross-piece 43 Y secured to the.soundin'g board!) is rigidly attached to and conneetedwith the armature 5 by .a' pin 44, saidpin-44 being straight and arran ed normally to the plane of said sounding'hoard 9. Thus the vibrations of the armature 5 produced by the electromagnet 1 are transmitted to the sounding board 9 the operation of which is enhanced by the sympathetic vibrationof .thesound of tones which'can .be reproduced-by the sound producer without unwished secondary sounds, a second resonance board 45 is proox. i a In-order still furtherto enhance thejscope vided in the sound box. The pin 44 freely passes through this soundingboard 45 and the two sounding boards 9 and 45 are connected" by two bridges 46 if so desired, but this second resonance board 45 may ted in most cases. g

The sound producer according to the invention need not have only a circular shape, but can-alsobe quadrangular, quintangular, or. of any other polyangular shape. It is may be constructed without departing from the spirit of our.invention.

We claim: i

1; In a combination with a telephone receiver. a resonanceboard, a pin rigidly attached -to and connecting said resonance board-with the armature of the said telephone receiver, said pin being straight and arranged normally to the plane of said res onance board, and a resonating body connected to said resonance board.

ceiver, a resonance board, a cross piece on said resonance board, a pin rigidly attached to and connecting the armature of the telephone receiver with said cross piece on the resonance board, said pin being straight and arranged normally to the plane of said resonance board, and a resonating body connected to said resonance board.

" 3. In combination with a telephone receiver, a resonance board, a pin rigidly attached to and connecting said resonance be omit- 2. In comb'nation with a telephone re-' boardwwith the armature of the saidtele- 9 phone receiver, said pin being straight and arranged normally to the plane of said resonance board, a second resonance board havlng an oscillation transmittlng connect1on w th the first one, and a resonating 5 said resonance body connected .boards. a v

'4. In combination with a telephone receiver, a resonance board, across-piece on 'to and connecting the membrane of the telephone receiver with said cross-piece on the resonance board, said 'pin being straight and arranged normally to the plane of said res-' onance board, and a resonating body. conto the said two resonance board,'a pin rigidly attached signatures.

magnet and arranged parallel to said resonance board, means for securing an oscillation-transmitting and rigid attachmentan'd connectionofsaid membrane with said resonanceboard, a second resonance board having an osclllation-transrnittmg connection w th the first one, and a resonating body connected to the said two resonance In testimony whereof we haveafiixed onr FRITZ W ILEELMQ KARL JOHANNES MULLER. 

